PROFESSIONAL MOTORSPORT
SIMULATION SOFTWARE
The extreme rpm test the assumptions within the model
The normally aspirated F1 engines as they were used from 2006 till 2011, propose an opportunity to test the model into an extreme direction.
The principle of these engines are the same as all other engines, just they are extremely pointed towards top end power. Big bore, very small stroke, very high revs. The rest similar like other engines.
Bore x Stroke:
Compression ratio:
Mechanical Losses:
98 x 39.7 [mm] (8 Cylinder)
13 : 1
0.8 [Bar]
Intake Valves:
Exhaust Valves:
2 x 39 [mm]
2 x 34 [mm]
Inlet Camshaft :
Exhaust Camshaft :
245 [mm] (@ 1 [mm] lift)
226 [mm] (@ 1 [mm] lift)
Intake runner:
Primary exhaust:
250 x 60 [mm]
550 x 50 [mm]
Different statements between 730 - 770 [Hp]
Playing with the parameters, we end up with the power and torque figures as seen above. In the media the engine were stated to have something around 750 [Hp], so we are quite close.
In order to fill the cylinders, it is actually not even necessary to go to extreme with the camshaft timing. The big bore enables big valves, are the key elements for the very high power output.
The model comes to this characteristics with all the main parameters the same as with the other race engines. So overall valve resistance, exhaust back pressure, fuel burn rate and mechanical losses of the engine.
Extreme test for burn and valve resistance model
Looking at the fill rate of the cylinders as a function of engine rpm, one can see that the fill rate is dependent on the gas dynamics.
The combination of big valves together with a longer duration camshaft, causes quite some backflow at low rpm, reducing the fill rate.